The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government.
Know the risks and potential benefits of clinical studies and talk to your health care provider before participating.
Read our disclaimer for details.

This phase II trial studies how well estradiol works in treating patients with estrogen receptor beta (ER beta) positive, triple negative breast cancer that has spread to nearby tissue or lymph nodes or other places in the body. Hormone receptors like ER beta allow the body to respond appropriately to hormones. Triple negative means that the breast cancer does not express other hormone receptors called ER alpha, progesterone, and HER2. In some people with triple negative breast cancer, ER beta is overexpressed. Tumor cells that overexpress ER beta grow slower in the laboratory and this growth is slowed in the presence of estrogen. Estradiol is a form of estrogen. This study may help doctors determine whether tumor cells that overexpress ER beta shrink in the presence of estradiol.

I. To assess the anti-tumor activity of estradiol in patients with locally advanced or metastatic triple negative breast cancer (TNBC) that expresses ERbeta (> 25% moderate or strong nuclear staining) and who have prior receipt of taxane and anthracycline based chemotherapy.

SECONDARY OBJECTIVES:

I. To examine the safety profile of estradiol when administered at a dose of 2 mg three times daily (tid) to women with locally advanced or metastatic TNBC that expresses ERbeta.

II. To examine the changes in phosphorylated (phospho)-ERbeta, cystatins 1, 2, 4 and 5, phospho-Smad2/3 and Ki-67 in tumor biopsies taken before and after the first cycle of treatment.

Assessed by Response Evaluation Criteria in Solid Tumors (RECIST) criteria for complete response (CR), partial response (PR), or stable disease (SD) for > 6 months following initiation of treatment. The 6 month clinical benefit rate is the percentage of patients who are found to meet the criteria for clinical benefit at least 6 months among all the patients who have started estradiol treatment.

Secondary Outcome Measures :

Incidence of adverse events [ Time Frame: 5 years ]

An adverse event (AE) is any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medical treatment or procedure that may or may not be considered related to the medical treatment or procedure. All grade 2, 3, 4 or 5 adverse events will be documented and assigned an attribute by treating clinician as to its relationship to treatment. For a given AE, the proportion of patients who report developing a grade 2-5 of this AE are determined. The number of dose reductions per patient and the reasons for the dose reduction are summarized.

Tumor response rate [ Time Frame: 5 years ]

The tumor response rate is defined as the 100% time the number of patients with a CR or PR (as defined by the RECIST criteria) on 2 consecutive evaluations at least 8 weeks apart divided by the total number of eligible patients who began study treatment. A 90% binomial confidence interval is constructed for the true response rate.

Progression free survival (PFS) distribution [ Time Frame: From randomization to the first of the following events: local, regional, or distant recurrence, second primary disease of death due to any cause, assessed up to 5 years ]

The distribution of PFS times will be estimated using the method of Kaplan-Meier.

Overall survival distribution [ Time Frame: From randomization to death due to any cause, assessed up to 5 years ]

The distribution of survival times are estimated using the method of Kaplan-Meier.

Patients undergo tumor biopsies prior to the start of treatment and at completion of cycle 1 treatment. These specimens will be undergoing immunohistochemistry (IHC) staining with the following antibodies: phosphorylated (phospho)-ERbeta, cystatins 1, 2, 4 and 5, phospho-Smad2/3 and Ki-67. For each of these biomarkers, a times series plot are constructed so that an individual patient?s data will be represented using the same color for each of the five graphs. These graphs are visually inspected for trends within each of the graphs (variation between individuals) as well as across the five graphs (profile of biomarker changes within an individual).

Other Outcome Measures:

Changes in serum cystatin levels in response to treatment [ Time Frame: 3 years ]

Change in cystatin levels following one cycle of treatment are examined using signed rank tests and the difference in the percent change in its level following one cycle of treatment between patients who derived clinical benefit and those who did not will be examined using a two sample Wilcoxon rank sum test.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information

Ages Eligible for Study:

18 Years and older (Adult, Older Adult)

Sexes Eligible for Study:

Female

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Individuals of all races and ethnic groups are eligible for this trial.

Note: Patients who are on anticoagulant therapy for maintenance are eligible as long as the DVT and/or PE occurred > 6 months prior to pre-registration, and there is no evidence for active thrombosis (either DVT or PE).